1. Field of the Invention
This invention relates to theatrical equipment and more particularly to an improved arrangement for raising and lowering a batten which supports theatrical equipment.
2. Description of the Prior Art
Theatrical stage equipment includes equipment which is required to be raised and lowered prior to and during a performance, in order to provide a desired scene effect. This equipment includes various rigging sets such as curtains, borders, screens, scene displays, and, various lighting fixtures. The rigging sets, which are generally coextensive in length with a proscenium opening of the theatre can be of substantial area and these sets, as well as the rigging lighting can have substantial weight. In relatively large theatres adapted for elaborate scene changes, the aforementioned rigging sets can number as many as about seventy which are generally aligned in parallel with the proscenium opening.
Rigging sets are generally secured to and are supported along a length by relatively narrow, elongated bodies known as battens. The batten typically comprises an elongated pipe, rod or rigid strip of material. Each batten is supported along its length by a plurality of flexible ropes which comprise, for example, wire ropes, manila ropes, etc. Elevating and lowering the batten is accomplished by an arrangement which includes a plurality of pulleys, a counterweight known as an arbor, an arbor pulley and an arbor drive block. Each of the plurality of ropes extends from a batten to an associated pulley which is mounted aloft and converge toward, extend about in engagement with, and extend away from the head block vertically downward and are coupled to the counterweight arbor. A rope which is coupled at two points to the arbor extends to a pulley mounted aloft and, at stage level, to an arbor drive block. Movement of the arbor rope is accomplished either manually by hand, or by driving the arbor block with an electric motor. The arbor is thus raised and lowered resulting in vertical motion of the batten and the supported rigging set.
It will be appreciated that in the relatively larger stage arrangements, the aforementioned rigging set support including ropes, pulleys, head block, arbor, arbor pulley and arbor drive mechanism occupies substantial space both aloft and at stage floor. The arbor drive is positioned on the stage floor and arbor drive ropes extend vertically from the stage floor at a location at side stage. This utilizes a substantial area of side stage floor space and this requirement becomes pronounced in relatively large theatrical arrangements wherein the rigging sets number up to about seventy. The raising and lowering of a relatively large number of battens supporting theatrical equipment thus places a substantial demand on the available stage space and increases the complexity of the arrangement.
In addition to providing a means for raising and lowering the batten, it is also desirable, from a safety viewpoint, to provide a means for locking a batten at a selected height so as to inhibit an accidental failure and a rapid uncontrolled descent of a rigging set which can result in injury to parties in the vicinity of the falling set. The aforementioned arrangement provides for locking through inhibiting rotation of the arbor drive pulley, either through a ratchet locking means or a brakeshoe arrangement. A safety lock is thus provided at stage level and suffers from the disadvantage that the locking is mechanically remote from the supported batten in that the locked member is coupled to the batten through intermediate members which are susceptible to failure.